[Raku LibXML Project] / [LibXML Module] / XPath :: Expression

class LibXML::XPath::Expression

Interface to LibXML pre-compiled XPath Expressions

Synopsis

use LibXML::XPath::Expression;
my LibXML::XPath::Expression $compiled-xpath .= compile('//foo[@bar="baz"][position()<4]');

# interface from LibXML::Node

my $result = $node.find($compiled-xpath);
my @nodes = $node.findnodes($compiled-xpath);
my $value = $node.findvalue($compiled-xpath);

# interface from LibXML::XPath::Context

my $result = $xpc.find($compiled-xpath, $node);
my @nodes = $xpc.findnodes($compiled-xpath, $node);
my $value = $xpc.findvalue($compiled-xpath, $node);

my LibXML::XPath::Expression $compiled .= new: :expr($xpath-string), :$node;

Description

This is a Raku interface to libxml2’s pre-compiled XPath expressions. Pre-compiling an XPath expression can give in some performance benefit if the same XPath query is evaluated many times. LibXML::XPath::Expression objects can be passed to all find... functions in LibXML that expect an XPath expression.

Methods

method new

method new(
    Str :expr($xpath)!, LibXML::Node :node($ref-node)
) returns LibXML::XPath::Expression

The constructor takes an XPath 1.0 expression as a string and returns an object representing the pre-compiled expressions (the actual data structure is internal to libxml2).

method compile

method compile(
    Str $xpath,
    LibXML::Node :node($ref-node)
) returns LibXML::XPath::Expression;

Alternative constructor which takes a positional XPath expression as a string.

Copyright

2001-2007, AxKit.com Ltd.

2002-2006, Christian Glahn.

2006-2009, Petr Pajas.

License

This program is free software; you can redistribute it and/or modify it under the terms of the Artistic License 2.0 http://www.perlfoundation.org/artistic_license_2_0.